The Yokohama Bay Stars announced on October 11 that thirty-two-year-old Tatsuya Shimozono and thirty-one-year-old Yota Kosugi are retiring.

Shimozono got his professional start with the Bay Stars in 2007. He played in a career high 131 games in 2010 and recorded a slash line of .286/.365/.376. Outside of that one season, he never played in more than ninety games in a year. He was the chief player representative between 2013 and 2015. He decided to retire because he wanted to end his career with the Bay Stars.

Kosugi began his professional career with the Bay Stars in 2009. He pitched in eighty-six Ichi-gun games and made fourteen starts over his career. This year was the first time he failed to pitch in an Ichi-gun game. He decided to retire because he was finding in increasingly more difficult to get himself ready to play.